Key legal question
Whether the mixed sale-donation of the villa was voidable for essential error under Art. 23 and 24(1)(4) CO because the seller expected future care and attention from the buyers.
Extracted holding
No. The expected future care was too uncertain and contingent to qualify as an essential factual assumption under Art. 24(1)(4) CO.
Extracted reasoning
An essential error may concern future facts only if, at contract conclusion, they could objectively be regarded as certain. The buyers' future solicitude was merely expectative and aleatory; therefore it could not be treated as an essential contractual element, even if the seller subjectively considered it important.